<template>
      <div style="border: 3px solid pink; margin: 10px;">
      son{{ title }}
        <button @click="changeFn"> 修改title</button>
    </div>
</template>

<script>
export default {
  props:['title'],
  methods:{
    changeFn(){
      this.$emit('changeTitle',"哈哈")
    }
  }
}
</script>

<style>

</style>